Or Not Edit Meaning

1.

Usually a sarcastic comment made after somebody pitches an idea. Otherwise, it can be said when someone is really excited about an idea that you think is stupid.

Person 1: "We could go play DDRat my house." Person 2: "...Or not."

Person 1: "Hey, you guys! I'm so excited about object!!!" Person 2: "...Or not."

See Aimee

2.

what she said. a cool phrase.

Person 1: "Justin Timberlake is so cool. I mean he's got all the girls after him and he dances like wild fire. You've gotta say he's uber fit looking too..."

Person 2: "...or not"

See brendan